Fix “Operating System Not Found” Errors

Sometimes Windows Update will go wrong in some way, rendering Windows unusable. It can also happen when a drive update goes wrong, or if you try and install more than one version of Windows on the same machine. This can often be fixed with a Startup Repair.

Choose your operating system (there will likely be only one listed), then click Next again

Select Use Recovery Tools That Can Help Fix Problems Starting Windows and click Next

Click Startup Repair

Your PC will restart again. Take the disc out and change the boot order in your BIOS back to starting from the hard drive first, if necessary. Windows should be working.

At this point, try Windows Update again and see if it wants to reinstall it. If the same problem happens again, try repeating the first eight steps above. After clicking Repair your Computer, choosing an operating system and clicking Next,